首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   266篇
  免费   5篇
耳鼻咽喉   10篇
儿科学   19篇
妇产科学   15篇
基础医学   8篇
口腔科学   14篇
临床医学   20篇
内科学   57篇
皮肤病学   1篇
神经病学   19篇
特种医学   5篇
外科学   69篇
综合类   9篇
预防医学   5篇
眼科学   4篇
药学   6篇
肿瘤学   10篇
  2021年   4篇
  2020年   2篇
  2019年   5篇
  2018年   5篇
  2017年   3篇
  2016年   4篇
  2015年   6篇
  2014年   3篇
  2013年   9篇
  2012年   21篇
  2011年   12篇
  2010年   6篇
  2009年   8篇
  2008年   21篇
  2007年   37篇
  2006年   29篇
  2005年   19篇
  2004年   17篇
  2003年   15篇
  2002年   16篇
  2001年   1篇
  2000年   3篇
  1998年   5篇
  1997年   1篇
  1996年   4篇
  1995年   1篇
  1991年   3篇
  1990年   3篇
  1989年   2篇
  1987年   1篇
  1984年   2篇
  1983年   2篇
  1978年   1篇
排序方式: 共有271条查询结果,搜索用时 15 毫秒
61.
BackgroundCrimean-Congo hemorrhagic fever (CCHF) is a tick-borne viral hemorrhagic disease. Pathogenesis of the disease has not been well described yet. A well-known pathogenic feature of CCHF virus is its capability to damage endothelium. Increased hyaluronic acid (HA) levels indicate liver sinusoidal endothelial damage. Soluble intercellular adhesion molecule-1 (sICAM-1), soluble vascular cell adhesion molecule-1 (sVCAM-1) and vascular endothelial growth factor-A (VEGF-A) play a role in the inflammatory process, vascular damage and plasma leakage.ObjectivesTo investigate whether or not there is a relationship between HA, sICAM-1, sVCAM-1 and VEGF-A serum levels and fatality in CCHF.Study designSixty-one patients who were confirmed by RT-PCR and serological tests for CCHF, included in the current study. HA, sICAM-1, sVCAM-1, VEGF-A levels in serum samples were analyzed by ELISA.ResultsThere were statistically significant differences between fatal and non-fatal CCHF patients in terms of HA, sICAM-1, sVCAM-1, and VEGF-A levels. In addition, AST and ALT levels were positively correlated with HA, sICAM-1, sVCAM-1, and VEGF-A levels.ConclusionHA, sICAM-1, sVCAM-1, and VEGF-A levels of the patients that died during hospitalization were statistically significantly higher than the patients that survived, and this finding suggests that the level of these molecules could be used as a prognostic marker in CCHF.  相似文献   
62.
BackgroundWe hypothesize that dexmedetomidine (DEX), a selective α2 adrenergic receptor agonist, may affect the intraoperative blood loss and clotting tests such as prothrombin time, activated partial thromboplastin time, and international normalized ratio in children undergoing adenotonsillectomy (ADT).MethodsSixty patients scheduled for elective ADT under general anesthesia. The patients were randomly assigned to receive either DEX 0.5 μg/kg (group D) or placebo bolus (group C) with a total volume of 10 mL, 10 min before the induction of anesthesia. Mean arterial pressure (MAP), heart rate, blood loss, preoperatively and immediately after awakening clotting tests, agitation, sedation, visual analog scale, and analgesic requirement, were assessed and recorded.ResultsThe postoperative hemoglobin was significantly lower than the preoperative value in both groups (P < 0.05). The postoperative agitation scale and analgesic requirement and visual analog scale at the 15th min were significantly lower in group D than those in group C (P < 0.05). Total blood loss and postoperative sedation score in group D was significantly higher than that in group C (P < 0.05). The postoperative prothrombin time, activated partial thromboplastin time, international normalized ratio tests between the groups, additionally pre-postoperative MAP, heart rate, and clotting tests were similar in each group.ConclusionsThe premedication with DEX 0.5 μg/kg decreased postoperative agitation, pain, and analgesic requirement without significant change in the clotting tests and MAP but increased bleeding slightly during ADT.  相似文献   
63.
 Fungal infections are a major problem among patients with hematological malignancies. To evaluate the efficacy of itraconazole (200 mg twice daily) in the prophylaxis of fungal infections in neutropenic patients, we conducted a prospective trial. A total of 61 patients with acute leukemia (113 cytotoxic chemotherapy episodes) were enrolled in the study. One patient in the itraconazole group was excluded because itraconazole was not taken due to gastrointestinal hemorrhage. Because the duration of neutropenia (neutrophil count, <0.5 × 109/l) did not reach 7 days, 3 (1 patient) and 13 (4 patients) cytotoxic chemotherapy episodes in the itraconazole and control groups, respectively, were excluded. After these exclusions, the study population consisted of 31 patients (54 cytotoxic chemotherapy episodes) who had taken itraconazole and 24 patients (43 cytotoxic chemotherapy episodes) who had not taken itraconazole. Prophylactic treatment was initiated on the first day of chemotherapy and was continued until the end of the neutropenic period (absolute neutrophil count, >1 × 109/l) unless a systemic fungal infection was documented or suspected. Thirteen episodes (24%) in the itraconazole group and 7 episodes (16%) in the control group proceeded to intravenous amphotericin B (P > 0.05). Fungal infections occurred in 9 episodes (17%) in the itraconazole group and in 5 episodes (12%) in the control group (P > 0.05). Overall mortality was five deaths in the itraconazole group and two in the control group. These deaths were not due to clinically documented fungal infection. In our study, efficacy of itraconazole in the prophylaxis of fungal infections in neutropenic patients was not detected. Received: March 25, 2002 / Accepted: October 1, 2002  相似文献   
64.
The purpose of this investigation was to assess hypoxic test effects on left and right ventricular contractility in patients with progressive systemic sclerosis (PSS) and pulmonary arterial hypertension (PAH). Ten patients (mean age 48.8±13.2 years) who were diagnosed with PSS and PAH were included in the study. All the patients underwent left and right heart catheterization. Right ventricular (RV) contractility was measured according to the method of Ferlinz [1] and left ventricular (LV) contractility according to the method of Kennedy et al. [2] using indirect digital substraction angiography. The mean pulmonary artery pressures ( PA) and oxygen saturation of the pulmonary artery (SaO2) were registered at each stage of graded hypoxic exposure 14%, 12%, and 10% of O2. Right atrial pressures (PRA,syst, PRA,diast, RA), right ventricular pressures (PRV,syst, PRV,diast, RV, PRV,end-diast), right and left ventricular end-diastolic volume index (EDVI), end-systolic volume index (ESVI), stroke volume index (SVI), cardiac index (CI), ejection fraction (EF), and heart rate (HR) were calculated before and after breathing a hypoxic mixture of 10% of O2 for 30 minutes. The hypoxic test induced significant elevation (p<0.05) of PA, PRA,syst, PRA,diast, RA, PRV,syst, PRV,end-diast, RV EDVI, LV, EDVI, CI, and HR, whereas, SaO2 decreased significantly after the hypoxic test. These findings suggest that patients with PSS and PAH are characterized by hyperreactivity of pulmonary artery to hypoxia and the preservation of compensatory mechanism of RV and LV contractility.  相似文献   
65.
OBJECTIVES: Bisphosphonates (BPs) are mostly used in the palliative care of myeloma-associated osteolytic lesions. Recent studies have suggested that BPs may also exert direct antitumor effects on myeloma cells. We have investigated the effect of the potent bisphosphonate, zoledronic acid (ZOL), on the development of pristane (2,6,10,14-tetramethylpentadecane)-induced plasmacytoma (PCT) in six-week-old BALB/c mice. METHODS: Different groups of pristane-treated mice also received ZOL (100 microg/kg) commencing after the development of PCT or ZOL (20 microg/kg) from the first day. Control groups received pristane alone, ZOL alone (20 microg/kg), or phosphate-buffered saline. The study was terminated on day 300, and the remaining mice were autopsied and abdominal tissues were examined histologically for PCT. RESULTS AND CONCLUSIONS: Statistical analysis revealed a significant delay in PCT development in the group receiving pristane plus ZOL (20 microg/kg) from the first day compared to the groups receiving pristane alone and pristane combined with ZOL (100 microg/kg) after the appearance of PCT (Log-rank, P = 0.0001 and 0.0001; respectively). Kaplan-Meier analysis revealed a significant difference in survival between the group treated with pristane alone and the groups receiving pristane plus ZOL (20 microg/kg) from the first day or ZOL (100 microg/kg) after the appearance of PCT (Log-rank, P = 0.016 and 0.023; respectively). These results indicate a direct anti-tumor effect of ZOL in pristane-induced PCT development BALB/c mice, which may contribute to their significantly increased survival. This hypothesis should now be further investigated in clinical trials.  相似文献   
66.
DNA repair systems are essential for cellular functions. Defects due to sequence variations in DNA repair genes can lead severe failure of cell functions and causing many cancer types including leukemia. The aim of this study was to investigate the relationship between XRCC1 Arg399Gln and XRCC3 Thr241Met polymorphisms and susceptibility to chronic lymphocytic leukemia (CLL) in Turkish patients. In addition, genotype distribution of these polymorphisms was compared with other populations. The frequencies of Arg399Gln and Thr241Met single nucleotide polymorphisms were studied in 25 CLL patients and 30 healthy individuals. Single nucleotide polymorphisms were genotyped by PCR–RFLP method. The genotype and allele frequencies of Arg399Gln and Thr241Met polymorphisms were not statistically different between the CLL patients and control group. The allelic frequency similarities were found between Turkish and Brazilian populations for Arg399Gln polymorphism. On the other hand, similarities were found between Turkish and other Caucasian populations for Thr241Met polymorphism. Marked differences were observed between American African versus Turkish and Chinese versus Turkish populations for Arg399Gln and Thr241Met polymorphisms respectively. These results indicate that Arg399Gln and Thr241Met polymorphisms were not associated with the development of CLL in Turkish population and ethnic differences is one of the most important factor for allele frequency differences.  相似文献   
67.
68.
PURPOSE: In our country, safety pin ingestion by infants is commonplace. When swallowed, open safety pins are mostly found within the esophagus or stomach, and they cannot be easily removed by rigid esophagogastroscopy. Our aim was to evaluate the removal of safety pins using flexible endoscopy in infants. MATERIALS AND METHODS: We evaluated the cases of 7 infants who had ingested open safety pins between 2001 and 2004. In all the patients, the primary diagnostic tool was a direct x-ray of the neck, chest, and abdomen. In all cases, the safety pins were removed by flexible esophagogastroduo-denoscopy. Clinical records for the cases were reviewed. RESULTS: Four of the open safety pins were lodged in the esophagus, two in the stomach, and one in the duodenum. One infant had a safety pin lodged in the esophagus with the pin's open end pointed caudally; the pin was held with the endoscopic forceps by its tail end and removed. Three safety pins in the esophagus had their open ends pointing cephalad; these were held by their tail ends using the endoscopic forceps and pushed into the stomach. Then they were rotated in the stomach and removed tail end first. The safety pins located in the stomach or duodenum were also removed similarly. All safety pins were successfully removed, and there were no operative complications. CONCLUSION: Open surgery or other invasive removal methods are not necessary in infants with open safety pin ingestions. In our opinion, the best way to extract an open safety pin from the esophagus, stomach, or duodenum is by using a flexible endoscopic device.  相似文献   
69.
A 60-year-old man with a history of a prior double-valve replacement (DVR) and permanent pacemaker implantation underwent mitral valve reoperation due to a paravalvular leak. Reoperation was performed on a beating heart (BH) on cardiopulmonary bypass, by perfusing the heart continuously with oxygenated noncardioplegic normothermic blood via the coronary sinus. We report the case of a patient who underwent mitral valve reoperation on a beating heart, 10 years after his first double-valve replacement and permanent pacemaker implantation.  相似文献   
70.
BACKGROUND: Comparison of neurological parameters in patients undergoing prosthetic heart valve replacement with two operating techniques-either cardioplegic arrest of the heart under hypothermic cardiopulmonary bypass (CPB) or the heart beating on normothermic bypass, with or without cross-clamping the aorta, without cardioplegic arrest. methods: Fifty valvular surgery patients were randomly assigned into three groups. Sixteen patients underwent beating heart valve replacement with normothermic bypass without cross-clamping the aorta, 17 patients underwent the same procedure with cross-clamping the aorta and retrograde coronary sinus perfusion, and the remaining 17 patients had conventional surgery with hypothermic bypass and cardioplegic arrest. RESULTS: Two-channel electroencephalography (EEG) was recorded to assess changes in cerebral cortical synaptic activity and 95% spectral edge frequency values were recorded continuously. Bispectral monitoring was used to measure the depth of anesthesia. Blood flow rates in middle cerebral artery (MCA) were measured by transcranial Doppler (TCD). Reduction in spectral edge frequency (>50%) or bispectral index (BIS) (<20) or transcranial Doppler flow velocity (>50%) was detected in four patients in Group 1, five patients in Group 2, and three patients in Group 3. BIS or EEG values never reached zero, which indicates isoelectric silence during surgery. Gross neurological examinations were normal in all patients postoperatively. CONCLUSION: There is no difference regarding neurological monitoring results between on-pump beating heart and hypothermic arrested heart valve replacement surgery. Also no significant difference was encountered among the groups regarding the clinical outcomes.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号